I agree that it's mostly a problem with the general direction of pop culture, but I'd also say that it's emblematic of problems with the baby boomers generally (I know I'm generalizing here).
I'm not naive, I know that RS was always a moneymaking exercise, and there was no "golden age." But in the 60s and 70s it seemed as if they took their jobs as cultural arbiters seriously and were writing about cool and interesting people (bloated, self-important hippie-ness notwithstanding). Now it just seems like a naked commercial enterprise, but still with all of the pretentiousness intact. I can agree or disagree with whether or not someone likes The Decemberists or something, but there's no reason to put, say, Christina Aguilera on the cover except to sell copies, or to be an organ of the music business.
I actually like the political reporting much better than the music reporting, though. Matt Taibbi is full of shit sometimes (but he's massively entertaining), and the Obama sycophancy is a little embarrassing. But there's usually one really solid piece of investigative journalism per issue.
I would never read the thing except that I got a subscription with some concert tickets and I can't figure out how to make it stop. I don't think I'm even paying for it anymore.
Fun fact: about a decade ago I cater-waitered a party at Jann Wenner's house where everyone was famous. I got drunk in the kitchen with a co-worker and got yelled at by Wenner for misidentifying one of the guests as Bianca Jagger. He's obscenely rich and has a whole bunch of Picassos. Art Garfunkel smoked pot in a guest bedroom and make a funny joke when I walked in on him, Senator Chuck Schumer has a pregnancy belly, and Harrison Ford is just like his character in Regarding Henry. I considered calling in about this during the celebrity sightings show.